Removal of Cr (VI) from Aqueous Solutions by Titanate Nanomaterials Synthesized via Hydrothermal Method

Titanate nanomaterials (TNs) were synthesized via a simple hydrothermal method. The physical-chemical properties of the as-prepared TNs, such as morphology, structure, surface area, and chemical composition, were characterized by XRD, SEM, and BET. The absorption capability and adsorptive mechanism of Cr (VI) in aqueous solutions were tested in the static system. The results showed that the TNs prepared with reaction time of 24 h were in pure monoclinic phase which aggregated mutually to form a unique layered structure. TNs were considered excellent adsorbents to Cr (VI). When pH 1, the adsorption capacity was up to 83.91 mg/g. The adsorption kinetics of Cr (VI) followed the pseudo-first order model. The equilibrium adsorption time of TNs was 80 min. The Langmuir isotherm model fitted the equilibrium data best. The adsorption of Cr (VI) onto TNs was an exothermic process, and the adsorption process was mainly composed of electrostatic attraction. The structure of TNs basically remained unchanged after adsorption.